1. Technical Field
The present disclosure relates to P-I-N microcrystalline silicon structures and methods for manufacturing the structures, and, more particularly, to a P-I-N microcrystalline silicon structure of thin-film solar cells and a method for manufacturing the structure.
2. Description of Related Art
In a traditional P-I-N microcrystalline silicon structure of thin-film solar cells, the I-type layer is manufactured in a single step by mixing gas sources SiH4 and H2, wherein the amount of doped H2 in the total gas mixture is relatively high (for example, SiH4:H2 is 1:40), in order to enhance the crystallinity of the I-type layer. However, when the amount of the doped hydrogen is too high, the crystallinity will not increase accordingly. As a result, Voc and FF will drop, causing deterioration in efficiency of the component. Moreover, too much hydrogen is likely to cause damage in the P-type layer provided under the I-type layer.
A technique in which the I-type layer is formed through a single step with a gas mixture of SiF4, SiH4 and H2 has been proposed, whereby increasing nucleation of the I-type layer. Nonetheless, the erosion rate of fluoride is even higher than that of hydrogen, so despite that nucleation is increased through the single step with the addition of SiF4, the degree of damage caused at the interface between the I-type and P-type layers is widened, and internal defects in the I-type layer are also increased.